1. Field of the Invention
The present invention generally relates to a barrier film and a manufacturing method thereof. More particularly, the present invention relates to an organic/inorganic multi-layered gas barrier film and a manufacturing method thereof.
2. Description of Related Art
As the flexible substrates afford better pliability and design freedom, the flexible display panels become popular and thus quickly replace the rigid display panels. Compared with the rigid substrates, the flexible plastic substrates are cheaper, compatible with workability and safety requirements and suitable for display medium and roll-to-roll processes. However, certain drawbacks exist, including low temperature and chemical resistance, high permeability to oxygen and water vapour and large thermal expansion coefficients. Typical flexible plastic substrate has water permeation of 100˜10 g/m2/day (at 25° C.), which is unable to completely prevent water vapour and oxygen permeation, thus leading to device impairment. In order to avoid water vapour and oxygen permeation, specific material is coated between the plastic substrate and the electronic devices. Such tight-sealing barrier material has to be defect-free and pinhole-free when formed as a membrane or a film, and highly transparent or no absorption to visible light. Such material can be formed as a single-layered or multilayered laminate film for gas barrier purposes.
Flexible gas barrier films include inorganic layers (of metal oxides, metal nitrides or metal oxynitrides) and organic layers. The inorganic layers provide better gas barrier capability, while the organic layers can help maintain the flexibility of the barrier film. However, conventional gas barrier structures are mainly fabricated by alternatively laminating organic/inorganic films, but the adhesion between the organic material and the inorganic material is poor. If further treatment is performed to the surface(s) of the organic or inorganic layers for improving the adhesion there-between, the production cost will be increased. Also certain defects, such as pinholes, exist in the barrier films fabricated by the vacuum processes and cause the permeation of the oxygen and water vapour, leading to degradation of the electronic device and shorter life time. Further shortcomings include high-priced apparatus or systems for the vacuum processes, low yields and difficulties in fabrication of large-sized substrates.